Plagiarism and authorship disputes

Consider the following scenario. Two researchers who have collaborated on various projects have, in the past, jointly published a number of papers. While working on a manuscript from one of their joint projects, the researchers experience a profound difference of opinion regarding the direction of the current project, leading to the eventual break-up of their association. Soon after, one of the researchers moves to another institution in another country. A year later, the remaining researcher decides to finish writing the manuscript and submits it for publication with his name as the sole author.

By appropriating the joint manuscript and submitting it under his name has plagiarism taken place? Many individuals and institutions, including the National Science Foundation, would consider this scenario a form of plagiarism. However, although clearly an ethical breach has taken place, ORI would classify this situation as an authorship dispute, and not a type of scientific misconduct. Similarly, other instances of what might clearly be a case of plagiarism to some individuals and/or institutions may not be considered such by ORI. By the same token, there have been cases of misconduct where the individual was exonerated at the institution where the alleged misconduct had taken place, but was later investigated by ORI or NSF and found guilty of scientific misconduct.